Reactions of phosphate esters and related compounds involving mainly nucleophilic attack upon the phosphoryl group are being examined with emphasis on their catalysis. One major area is the role of a water-lipid like interface as the site of reaction, and the differences between this microenvironment and bulk water. Nucleophiles derived from choline are much more reactive than expected from their basicity and this problem will be examined in both micellar and non-micellar systems because interactions between quaternary ammonium ions and aromatic compounds are very important chemically and biologically. Functional micelles having reactive amino or hydroxyl groups at the head are good catalysts for decomposition of phosphate esters and they can act as general bases or as nucelophiles. It appears that in attack on phosphoryl groups alkoxide moieties function as nucleophiles, but amino groups act as general bases, and this area will be explored using substrates such as acyl phosphates where reaction can occur at either the carbonyl or phosphoryl groups.